QUINCY — Even before his trial on corruption charges, his Democratic friends had shunned him. During his disastrous run for governor, his own running mate deserted him and endorsed his Republican rival. It was little surprise when he garnered just 8 percent of the vote.

Now that his trial has ended in a deadlocked jury, former state treasurer Timothy P. Cahill is hoping to resume a quiet life in Quincy, working at a small investment firm in neighboring Braintree. Already a marginal figure in state politics, he is out of power and unlikely to run for office again.

He and his wife, Tina, insist that is just fine. On Thursday, Cahill, a normally effusive interview subject, stayed inside his Quincy home while Tina Cahill came to the door to speak with a reporter.

“Tim’s going to focus on his life in the private sector and get out and work and kind of regroup and refocus, what he wanted to do in the first place once the election was over,” she said. “That’s really what we want to do, put politics ­behind us.”

Immediately after the judge declared a mistrial Wednesday afternoon, the Cahills went to the North End. Tina Cahill, who was more open about the stress on the family during the five-week criminal trial, had a martini. The former treasurer sipped a cappuccino. They stopped at a church to say a prayer, returned home to ­receive friends, and turned in for an early night.

“It’s always been hanging over our head, and so now that it’s over, it’s a huge relief,” Tina Cahill said. “At the end, it ­became totally consuming, ­because it was every day, all day and all night.”

Their ordeal is not over, however. Because jurors failed to agree on a verdict, Cahill is still facing two counts of conspiracy, which is punishable by up to five years in prison. Attorney General Martha Coakley has not yet decided whether to retry the case. If she does not, she and Cahill could resolve the charges with a plea deal or a civil settlement involving a fine.

Brad Bailey, Cahill’s lawyer, said Thursday that his client would like the case to be ­referred to the State Ethics Commission, which can levy fines. But Cahill would sooner face a retrial than agree to any resolution that requires him to admit criminal wrongdoing, Bailey said.

Cahill, 54, was always seen as a surprising statewide office­holder. A scrappy high school wrestler, he opened a Quincy sandwich shop called Handshakes, served on the City Council in the late 1980s and early 1990s, and then made the jump to Norfolk County treasurer. He was elected state treasurer in 2002, distinguishing himself in a crowded field with an ad that featured his daughter urging voters to support “Tim for Treasurer.”

But his departure from the Democratic Party ostracized him from the political establishment, and his 2010 run for governor doomed his political career a year later.

After Wednesday’s mistrial, Cahill said his first priority, now that he has some time, was “probably raking leaves.”

He downplayed the toll on the family.

“We’re fine; we’re fine,” he said. “It’s been tough, but that’s all in the past. Now we’re looking to go forward.”

The mistrial allows Cahill to continue earning a living, at least for now, and to begin address­ing his extensive legal bills.

He has raised $60,350 with an official defense fund, of which $50,000 was loans from two sisters. He has yet to claim his state pension, but is expect­ed to receive about $42,000 a year, tax-free. A conviction would probably result in revocation of that annual payment.

Cahill said during the trial that he works for a Braintree financial management firm called Compass Securities. The firm’s website lists him as a registered representative. The president did not return phone calls or an e-mail seeking elaboration of Cahill’s respon­sibilities and future with the firm. A criminal conviction could jeopardize his ­license to work as an investment adviser.

Even if Cahill regains his finan­cial stability, a return to elected office seems unlikely. Whatever name recognition he garnered in his eight years as treasurer and in his run for governor appears to have vanished. During jury selection, lawyers found few jurors who had even heard of Cahill. His campaign operatives were ­depicted by his own defense team as hapless.

Political figures in Quincy, his onetime political base, seemed hesitant Thursday to speak about him while he ­remains under indictment. Several local officials dodged reporters’ phone calls or said they did not want to comment.

Quincy’s mayor, a supporter, would not take calls, instead issuing a statement, which also mentioned Cahill’s former campaign manager, Scott Campbell, who was acquit­ted of corruption charges Tuesday.

“Scott and Tim are two people that I know care deeply about their families, their neighbors, and their community,” Mayor Thomas P. Koch said. “I am very happy that this incredibly difficult ordeal is over for themselves and their loved ones. Like so many people in this city, I will always be proud to call them friends.”

Cahill said Wednesday that he will not run for office again, and his wife reiterated that Thursday. “We’re done, as a family,” she said. “It’s too bad that he ran for governor, and I think we were just naïve and didn’t understand how brutal the oppo­sition could be.”